Exploring the relationship between channel bed control structures and stream power in low-gradient floodplain wetlands

Timothy J. Ralph*, Zacchary Larkin, William Farebrother, Joanne Ocock, Tim Hosking, Tsuyoshi Kobayashi, Michael Hughes, Paul P. Hesse, Kirstie A. Fryirs

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference proceeding contributionpeer-review

Abstract

Floodplain wetlands are complex fluvial systems that provide critical ecosystem services. Some floodplain wetlands suffer from erosion that threatens to create and enlarge channels and potentially disconnect wetlands from vital overbank flows. Excessive channel erosion can have dramatic effects on flow routing, inundation patterns and aquatic ecosystem dynamics. Channel erosion is sometimes mitigated by the use of bed control structures to arrest bed lowering and associated channel enlargement. Stream power modelling techniques based on Digital Elevation Models (DEMs) have rarely been used in low‐gradient rivers and wetlands. A modified stream power modelling method was used to identify hotspots of enhanced stream power, and therefore potential erosion risk, in the Ramsar‐listed Macquarie Marshes, NSW. Peaks in stream power occur where pronounced steps exist in channel longitudinal profiles, most notably at rock bed control structures. In low‐gradient floodplain wetlands, local over‐steepening within the channel is associated with increased stream power and erosion potential. Stream power modelling provides an important screening tool to prioritise sites for detailed investigation and erosion assessment. Ultimately, such modelling can guide further monitoring and/or interventions to reduce the risk of erosion and ecological deteriorations.
Original languageEnglish
Title of host publicationProceedings of the 10th Australian Stream Management Conference, 2-4 August 2021
EditorsT. Boyd, M. Coker, S. Gregor, A. Miller, A. Morris, K. Russell, I. D. Rutherford, G. J. Vietz, J. Walker, A. Wood
Place of PublicationMelbourne
PublisherRiver Basin Management Society
Pages240-246
Number of pages7
ISBN (Electronic)9780646844916
Publication statusPublished - 2021
EventAustralian Stream Management Conference (10th : 2021) - Online
Duration: 2 Aug 20214 Aug 2021
Conference number: 10th

Conference

ConferenceAustralian Stream Management Conference (10th : 2021)
Abbreviated title10ASM
CityOnline
Period2/08/214/08/21

Keywords

  • channel erosion
  • discharge
  • hydrology
  • geomorphology
  • stream power

Fingerprint

Dive into the research topics of 'Exploring the relationship between channel bed control structures and stream power in low-gradient floodplain wetlands'. Together they form a unique fingerprint.

Cite this